What is the purpose of setting the brake on a train?

Setting the brake on a train primarily serves the purpose of preventing the rolling of cars to which coupling is made. When a train is stationary, particularly on an incline or when parked, it is crucial to ensure that the cars do not roll away. Engaging the brakes creates friction that holds the train securely in place, thus maintaining safety and preventing accidents. This is especially important during loading and unloading operations or when conducting inspections.

Other functions of brakes include controlling speed while descending slopes and preparing for stops; however, the immediate objective when setting the brake is to ensure the train's stability in a fixed position.